This forms the bulk of the heart tissue, because those cardiac muscle cells contract and pump blood.

他们构成了大部分心脏组织，这是因为心肌细胞能收缩，从而实现泵血。

After those pacemaker cells make themselves fire, they spread their electrical impulses to cardiac muscle cells throughout the atria.

这些起搏细胞自我激活后，它们将电脉冲传播到整个心房的心肌细胞。

Now this can be a cell that's part of the conduction system or it can just be another cardiac muscle cell.

这个细胞可能属于传导系统的一部分，或只是一个心肌细胞。

He has managed to reprogram mouse connective-tissue cells so that they develop into cardiac muscle cells, and has tested them in the hearts of mice that have had heart attacks.

他将小鼠结缔组织细胞重新编排，使其转变为心肌细胞，然后在心脏病小鼠的心脏中测试这些细胞的功能。

In addition to cardiac muscle cells, there are crisscrossing connective tissue fibers, which are made of collagen, that together form the fibrous cardiac skeleton, which helps support the muscle tissue.

除心肌细胞外，还存在交叉结缔组织纤维；这些纤维由胶原蛋白构成，它们一起形成纤维性心脏骨架帮助支撑肌肉组织。

Like skeletal muscle fibers, cardiac muscle cells have striations. Like smooth muscle fibers, each cardiac muscle cell has only one nucleus and its contraction and relaxation are not under conscious control. Therefore, it is also called involuntary striated muscle.

像骨骼肌纤维一样，心肌细胞也有条纹。像平滑肌纤维一样，每个心肌细胞只有一个核而且其收缩和舒张不受意识控制。因此，它也被称为非随意横纹肌。